Due to a flexible electronic device has features, such as light and thin, flexible, impact resistant, high safety and easy to be carried, the flexible electronic device play a major role in the next generation. Based on the design demand of narrow-edge layout or the signal conduction, the carrier board for the electronic components in a flexible electronic device often gets flexed or bent during assembling.
When the flexible electronic device is bent, the stresses will be concentrated at the bending places of the carrier board which get flexed or bent during assembling so as to lead to the phenomena of stress interference, stress creeping, carrier board's folding, local deformation or destroyed signal contacts (such as an external terminal area). How to take narrow-edge layout and solving the stress concentration into consideration becomes an issue for the technical staff to eagerly concern.